3.
XML Schema

The latest revision of the version 2.0 orm schema is presented below. Version
2.0 of the schema must be used if JPA 2.0 elements are specified as XML
metadata. Many of the elements in the schema relate to object/relational
mapping rather than metadata; these elements are discussed in
Chapter 13,
Mapping Metadata
. Version 1.0 of the orm schema can be
found at http://java.sun.com/xml/ns/persistence/orm_1_0.xsd.